1. Technical Field
The present invention relates to a semiconductor circuit, and more particularly, to a repair control circuit and a semiconductor integrated circuit using the same.
2. Related Art
A semiconductor integrated circuit 1 in the related art includes, as illustrated in FIG. 1, a plurality of unit memory blocks (hereinafter referred to as “MAT”), each of which is provided with a plurality of memory cells, a plurality of bit line sense amplifiers BLSA, a word line driver 10, and a repair control circuit 20.
The repair control circuit 20 includes, as illustrated in FIG. 2, a repair address generation unit 21, a comparison unit 22, and a repair unit 23.
The repair address generation unit 21 generates repair column addresses CRADDR<0:n> in response to a plurality of MAT selection signals MATSEL<0:n> and a bank active signal ActiveBK.
The comparison unit 22 activates a repair signal REP if the column addresses CADDR<0:n> and the repair column addresses CRADDR<0:n> coincide with each other.
The repair unit 23 activates a repair column selection signal RYi<c> if the repair signal REP is activated.
As a method to reduce time for testing in the related art, a plurality of word lines are simultaneously activated to reduce column access time tRCD after a read command and precharge time tRTP after a column access.
Referring to FIG. 1, a method for simultaneously activating a plurality of word lines WL<a> and WL<b> has been used to reduce time for testing.
However, this method is unable to be used after cells in which defects have occurred are repaired, and the reason is as follows.
If the plurality of word lines LW<a> and WL<b> are activated after the repair is performed, corresponding MAT selection signals MATSEL<0:n> are generated.
It is then required that a repair column selection signal RYi that corresponds to one repair column address CRADDR<0:n> is generated according to one MAT selection signal MATSEL<i>.
However, since the plurality of MAT selection signals, for example, two MAT selection signals MATSEL<i, j>, are simultaneously generated, the column selection signals Yi<a, b> that correspond to different column addresses are simultaneously activated, and this causes a column repair error to occur.
A wrong repair column selection signal RYi is activated instead of a normal column selection signal, and data which is different from the data that is required in a test operation is output that may cause a fatal problem.
Accordingly, the test method in the related art through simultaneous enabling of a plurality of word lines is unable to be used after the repair, and thus is not possible to reduce test time.